HISTORIE, TECHNIEKEN EN MAATSCHAPPELIJKE ...

An abundance of geographical names makes this map extremely important,
the nomenclature being almost all still in use to day. This map had become
urgently needed in connection with the granting of concessions, since the
official map for the balata industry, that of Cateau van Rosevelt, appeared
inadequate.
The Bakhuis map constructed according to the Mercator projection serves
even today as the official map for requesting and granting parcels of land
for concessions of any type.
7. The period of aerial surveying (1943-present)
7.1 The first photogrammetric surveys
The US Airforce conducted an aerial survey in Suriname in 1943 for the
purpose of making aeronautical maps. (World Aeronautical Chart). The sur-
vey was done according to the trimetrogon system while a comparison of
the thus produced maps with the one to a million map of Suriname from the
Central Bureau for Aerial Survey (C.B.L.) clearly points out the short-co-
mings of the beginning phase of photogrammetry.
An aerial survey of northern Suriname of higher quality was performed in
1949 by the Cartographic Service of KLM.
A total of 10,419 photos was taken in the scale 1:40.000.
As a necessary offshoot of this commission for the systematic photographic
recording, the C.B.L. came into existence (February 7th, 1948). The frame
work of surveying was formed by 26 astronomically fixed points according
to the Gauss-method; while for orientation on behalf of the aerotraingula-
tion traverses were measured.To obtain the elevation of the ground-con-
trol-points (astropoints) barometric observations were conducted at the site
and along the rivers, using the vertical datum of the Office of Lands-being
1,50 m below mean sea level.
The maps composed from the aerial photos were executed in the system of
the sterographic projection; having as central point the intersection of the
meridian of 55'411 West Longitude and the parallel of 4'07' North Latitude.
All geographic coordinates were calculated on the Bessel spheroid. An addi-
tional commission for mapping the southern part of Suriname (below 4' of
latitude) followed in 1956.
Airborn methods on behalf of the geodetic frame work
To set up a triangulation network of primary order, consisting of 52 points
equally spread throughout the country, the aerodist system was applied.
For orientation purpose this net was tied to some Hiranpoints. During the
first and second phase of the densification of this net the helidist method
was used and ground controlpoints were measured.
In areas where use of a theodolite was impossible, a modified helidist
method, known as "multidist" was applied. Still other problems presented
themselves related to the fixing of ground-control points, whereby neither
helidist nor multidist could be used. In those cases terrestrial methods such
as traversing and/or trilateration were applied.
Height-data were established partly by first order leveling and partly by
barometric measurements.
The adjustment of the aerodist net only, dit not provide a satisfactory re-
sult in all respects; an integral adjustment however of aerodist and helidist
measurements together yielded acceptable values.